Electric lighting by low-frequency currents.



No. 682,|84. Patented Sept. l0, 190i.

' W. G. FISH.

ELECTRIC LIGHTING BY LOW FREQUENCY CURRENTS.

(Application filed Jan. 26. 1901.)

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UNITED STATES PATENT OEEIQE.

\VALTER C. FISH, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRICCOMPANY, OF 'NEW YORK.

ELECTRIC LIGHTING BY LOW-FREQUENCY CURRENTS.

SPECIFICATION forming part of Letters Patent No. 682,184, datedSeptember 10, 1901.

Application filed January 26, 1901. Serial No. 44,776. (No model.)

To all whom, it ntay concern:

Be it known that I, WALTER C. FISH, a citizen of the United States,residing at Lynn, county of Essex, State of Massachusetts, have inventedcertain new and useful Improvement-s in Electric Lighting byLow-Frequency Currents, (Case No. 1,517,) of which the following is aspecification.

This invention relates to electric lighting; and its object is to enablealternating currents of low frequency to be used for illuminatingpurposes. Ordinarily a single-phase alternating current must have highfrequency in order to maintain an are without disagreeable flickering.with low-frequency currents it has been proposed to use multiphasecurrents and a plurality of electrodes, one for each lead of the circuitand one for the return or compensating wire, as set forth, for instance,in the patent to E. WV. Rice, Jr., No. 041,891. Vith an organization ofthis kind some one of the phases was always active in maintaining thearc, as there were no intervals of zero potential at the arc-terminals,and a steady light was produced at much lower frequency than was at thattime possible with a single-phase current. By my invention, however, alowfrequency single-phase current can be used to produce the sameresult, which I accomplish by providing two arcs or other illuminantsfed from the same single-phase lead, one or both of them, however, beingin circuit with or otherwise in operative relation to, a phase-modifyingdevice, so that the currents diifer in phase from one another. By thussplitting the phase, so to speak, the light is maintained during theinterval when a single are or the like wouldbe at zero potential. Theinvention is applicable to any kind of electric lamp,whether of the arc,incandescent or pyro-electrolytic type.

In the accompanying drawings, Figure 1 is a diagrammatic representationof an arc-lamp embodying my invention. Fig. 2 is a dia-.

gram of a modification. Fig. 3 shows a further modification. Fig. 4 is aview of the adjacent ends of three carbon electrodes. Fig.

5 shows the invention applied to an incandescent lamp. Fig. 6 shows itapplied to a pyro-electrolytic lamp.

To prevent this flickering Referring to Fig. 1, let A be a generatorofsingle-phase alternating currents feeding the leads 1 2. Two pairs ofcarbon electrodes B C B C are arranged parallel and close together,preferably both pairs inside of one globe D. One carbon of each pair hasa regulating-coil E E and clutch F F. Each coil is connected in serieswith its own carbon B B and is fed with single-phase alternating currentfrom the lead 1. Coil E takes its current through a non-inductiveresistance G, Fig. 1, or a condenser H, Fig. 2. Coil E takes its currentthrough an inductive resistance I. The lower carbons C C are bothconnected with the lead 2.

In operation the current flowing through the inductive resistance I lagsbehind that flowing through the non-inductive resistance G or condenserH by a certain angle which preferably should approach a quarter-phase.The result, if a true ninety-degree relation is secured, is that the arebetween the carbons B C rises to maximum potential when the are betweenthe carbons B C isat zero potential, and as the latter rises the formerfalls until, as the leading current passes the zeropoint, the laggingcurrent has reached its maximum. The two arcs are therefore continuallychanging in relative value, one rising either in the positive ornegative direction as the other falls. The light from the arcs, takingthem together, is thus maintained at nearly a constant value. Even witha phase displacement very much less than ninety degrees the light ismuch improved.

In Fig. 3 a single large lower carbon C is used in place of the twocarbons O C. (Shown in Figs. 1 and 2.) One of the upper carbons may besmaller than the other, as shown in Fig. 4, where the leading current isled through the smaller or auxiliary carbon B placed within arcingdistance of the lower carbon 0 The are between this auxiliary carbon andthe lower carbon will be sprung without difliculty on each wave, as atthe time when the potential rises in this circuit there is alreadyexisting astrong are between the two large carbons B C W'hen, however,the current in the lagging circuit is passing through zero, there willbe then a perceptible are between the auxiliar carbon and the lowercarbon, so that when the voltage in the lagging circuit rises either inthe positive or negative direction it will not be obliged to break out anew path foritself, but will pass through the auxiliary arc. Thus thepercentage of the wave which is dark is greatly reduced and a largerpercentage of light is obtained on low-frequency currents.

In Fig. 5 I have shown anincandescent lamp K, with one terminal of itsfilament connected with the main lead 1 through the non-inductiveresistance or condenser and the other terminal connected with the samelead through the inductive resistance. The middle of the filament isconnected with the other main lead 2, and in operation the halves of thefilament will become alternately bright and dim.

In Fig. 6 the two pairs of carbons are replaced by pyro-electrolyticilluminants L L, placed close together. A single transparent ortranslucent inclosure M may be used, if desired. As the displacedcurrent rises and falls a quarter-phase behind the leading current thetwo illuminants alternately increase and decrease in brilliancy.

Vhat I claim as new, and desire to secure by Letters Patent of theUnited States, is-

1. The combination with twoleadscarrying a single-phase alternatingcurrent of low frequency, of illuminants placed close together, andtaking current from said leads, and means for causing, in the normaloperation of the device, a relative phase'displacement of the currentflowing through said illuminants.

2. The combination with two leads carrying a single-phase alternatingcurrent of low frequency, of two illuminants placed close together, andconnected across said leads, and an inductive resistance in series withone of said illuminants.

3. The combination with two leads carrying a single-phase alternatingcurrent of low frequency, of two illuminants placed close together, andconnected across said leads,'an inductive resistance in series with oneof said illuminants, and a non-inductive resistance in series with theother.

4. The combination with two leads carrying a single-phase alternatingcurrent of low frequency, of two upper carbons placed close together andconnected to one of said leads, a single lower carbon in arcing relationto both the upper carbons and connected .with the other lead, means forindependently regulating the upper carbons, and means for causing aphase lag in the current flowing to one of said upper carbons.

5. The combination with two leads carrying a single-phase alternatingcurrent of low frequency, of a pair of carbons connected across saidleads, an inductive resistance in series therewith, and an auxiliarycarbon in arcing relation to the lower carbon of the pair and connectedwith the samelead as the inductive resistance.

In witness whereof I have hereunto set my hand this 22d day of January,1901.

VALTER O. FISH.

WVitnesses: DUGALD MoK. McKiLLoP, JOHN J. WALKER.

